1. Field of the Invention
The present invention pertains generally to an apparatus and method of bus arbitration for a distributed computer network and, more particularly, to a bus contention scheme which efficiently alleviates the simultaneous access possibility.
2. Description of the Contemporary and/or Prior Art
With the increased interest in distributive computer networks, it is necessary to develop an efficient bus arbitration scheme. One class of distributive computer networks has no centralized controller to control communication over a common bus. In such cases the individual computing elements must each contain an arbitration means to determine whether that particular element can obtain access to the common bus. (The term "computing element" as used in this application can be any node in a network, such as a terminal, microcomputer, personal computer, tape drive, or processor.) If two or more computing elements desire to simultaneously access the common bus, the arbitration means must decide which computing element gains control of the common bus.
Prior art contention schemes required all computing elements to "back off" and reinitialize bus entry procedures if two or more computing elements simultaneously attempted to transmit on the common bus. This "back off" scheme as described in Metcalfe et al (U.S. Pat. No. 4,063,220 issued Dec. 13, 1977) is inefficient and slow during periods of high traffic volume.